Individuals with ''extensive criminal associations'' are involved in legitimate business partnerships with major Australian sporting codes, leaving athletes exposed to exploitation and corruption through otherwise legitimate relationships.

The Australian Crime Commission report released on Thursday reveals it has uncovered evidence that ''illicit drug use by professional athletes remains an ongoing issue'' with official statistics of use within professional sports ''likely to significantly understate the extent of actual use''.

''Illicit drug use by athletes leaves them particularly vulnerable to exploitation for other criminal purposes, including match fixing and fraud arising out of the provision of 'inside information','' the report states. ''There is also evidence to suggest that some athletes are supplying others with illicit drugs.'' According to the director-general of the World Anti-Doping Association, the influence of organised crime in sport is increasing, with criminal groups involved in the trafficking of performance- and image-enhancing drugs also engaged in money laundering, corruption, match fixing and fraud.

''Overseas experience has also demonstrated that criminal identities and groups will invest years developing such relationships, with the ultimate aim of having the athlete participate in activities such as match fixing,'' the report states.

''Relationships between athletes and organised crime identities can be exploited by criminals to corrupt the athlete and give a form of social status to the criminal, in the same way that the steroid market has been used by organised crime to corrupt law enforcement officers.''

Police sources have told Fairfax Media intriguing relationships have emerged in recent investigations, although the lines between drugs, sport and celebrity ''have always been blurry''.

One example that raised eyebrows was revealed long before the ACC investigation, which has been running for the past 12 months.

In 2006 league legend Andrew ''Joey'' Johns was revealed to have gone into business with Eddie Hayson, co-owning as many as six racehorses. Hayson has been variously described as a ''controversial racing identity'', a ''brothel king'', and ''Australia's biggest gambler''.

Not long after the revelation, a betting plunge on the Newcastle Knights losing a match against Auckland led to a multimillion-dollar windfall for many, including Johns's friend and business partner Hayson. After the bets had been placed, it was revealed Johns was hurt and would not be playing.

There were more furrowed brows about how this had leaked out but the National Rugby League found no wrongdoing by Johns when it investigated the betting plunge.

Then in 2007 the retired Kangaroo admitted using recreational drugs such as cocaine and ecstasy during the last 10 years of his career. The fallout from the combined controversies has undoubtedly left the league legend tarnished. Hayson and his Camperdown brothel Stiletto are under the microscope as part of a multi-agency investigation into alleged drug and money laundering activities by the state and federal authorities.